The DVD Forum approved a 15GB single-layer HD DVD-R discs as Version 1.0 of a write-once HD DVD disc in February 2005. Toshiba continued development toward the newly announced 30GB dual-layer HD DVD-R disc, which uses a new organic dye jointly developed with a dye manufacturer.
The dual-layer HD DVD-R disc is based on the same disc structure as current DVD discs, HD DVD-ROM discs (read-only), and HD DVD-RW discs (rewritable): back-to-back bonding of two 0.6 millimeter-thick substrates. The new disc also shares key manufacturing processes with DVD-R: use of an organic dye as the data storage medium; and a spin-coating process for depositing the dye. As a result, disc manufacturers can minimize their investment in disc production equipment for dual-layer HD DVD-R by using already installed DVD-R manufacturing lines for mass production.
Toshiba and disc manufacturers will verify compatibility of dual-layer HD DVD-R discs in round robin testing at the DVD Forum, starting on October 17. Toshiba targets finalization of the specification book by the DVD Forum within the year.
Note: Capacity of a disc is calculated with a basis of 1-gigabyte (GB) = 1-billion bytes
